The present invention relates to a lost wax precision casting process and, more particularly, to a coating system for coating a wax pattern with a refractory material to make a set-up as a step of the lost wax precision casting process.
In this specification, a body consisting of runner and a wax pattern of the final product attached to the runner will be referred to as "wax pattern body". The body after the automatic coating operation will be referred to as "mold of refractory material accommodating a wax pattern". Also, the body under the automatic coating work will be generally referred to as "set-up".
Typical conventional work for making a set-up by coating a wax pattern with a refractory material includes arranging various equipments such as slurry tank containing slurry of refractory material and sanding device such as fluidized bed, and conveying and setting the wax pattern body manually in these equipments to coat the wax pattern body with a refractory material.
In order to obtain a sufficient strength of the set-up, it is necessary to repeat the coating operation to form a plurality of coating layers. As the coating operation is repeated, the weight of the half-finished set-up is gradually increased to require a large manual force to convey and set the half-finished set-up. In addition, the repeated work itself is monotonous and has to be made under an extremely severe condition of work. For these reasons, the coating work is the object of the laborer's aversion.
Under this circumstance, it has been proposed to use known robot or transportation jigs adapted for putting the half-finished set-up into and out of the slurry tank and sanding device. This, however, is only a partial mechanization of the coating work, and is not intended for the full automatic control of the whole coating work. Therefore, it is not possible to make the coating complying with coating requirements of various set-ups and, in addition, various additional works are required. On the other hand, there is an increasing demand for a full automatic coating system which would afford a mass-production to make the full use of the advantage peculiar to the lost wax process, in order to compensate for the shortage of the manpower and to cope with the current rise of the labor cost.